It's just that "the customer is always right" is the rule. You have to give 'em what they want. I can assure you, they don't want to be educated. I want the money, they want the work done the way they specify. I get the money if I give 'em that. If I do anything else, all bets are off.

Now, just because YOU can't think of any reason to use mode 0 doesn't mean there isn't one.

As I said, in the past, when the only devices available were 12-clockers, it wasn't realistic to use the "shift-register" mode simply because the MCU didn't have the bandwidth to dispose of the data within a byte-time, and do any other useful work. Now that there are one-clockers, things look different. If I use a one-clocker, I can bit-bang SPI if I want, and easily. If I want to bit-bang IIC, I can do that, too, and easily. If I want to perform conventional synchronous communication, I still have to do some work, even with the mode-0 serial port, since it doesn't know how to recognize or insert sync characters, etc. though, unless I want to bit-bang that as well, at which time, once again, it becomes a chore.

However, if I want to sample a signal containing serial data, I can do that easily now that the MCU has enough bandwidth to dispatch the data, and that's what mode-0 was intended to do.

If you want to process data from a codec, mode-0 handles it. If you want to conjure up a serial format not otherwise available, mode-0 is a likely candidate as well.

There are things you can do with mode-0 that you might not be able to achieve otherwise. There are things you shouldn't attempt with mode-0. There are also things for which you shouldn't ignore mode-0. It's up to you to know the difference.

RE